The development of an enzyme-controlled calcification model will be continued, with the use of alkaline phosphatase in polysaccharide gels to hydrolyze calcium salts of organic phosphates beta-glyceryl phosphate, phenyl phosphate and ATP). Studies of the effect of phosvitin on the nucleation of apatite on collagen fibers will be made and studies of the orientation of apatite crystals on the fibers will be carried out. Growth of crystals of apatite and other biologically important phosphates will be continued by gel and apatite and other biologically important phosphates will be continued by gel and aqueous diffusion methods. Studies of frequency-doubling as a test for non- centrosymetry will be continued on these materials in an effort to understand the piezoelectric properties of apatites and similar materials, including materials of biological origin. These properties will be further studied by infrared, NMR and Mossbauer spectroscopy of appropriately "doped" samples. These studies will help in understanding the function of Sn ions and F minus in the cariostatic applicaton of SnF2.